温度及无机盐对LMEE和SDS混合溶液表面张力的影响

Effect of Temperature and Inorganic Salt on Surface Tension of LMEE and SDS Mixed Aqueous Solution

通过表面张力的测定,研究了温度和不同无机盐对月桂酸甲酯乙氧基化物(laurylmethylesterethoxylate,简称LMEE)与十二烷基硫酸钠(SDS)复配物表面张力及临界胶束浓度(CMC)的影响。研究表明:混合体系的CMC在很宽的复配比例内出现最低值,25℃、未加无机盐时可使CMC最低降至3 8×10-5mol/L;温度对复配体系表面张力的影响较小,温度上升复配物的CMC略有降低。3种价态无机盐的加入均可使复配物的CMC有所降低,但与单一表面活性剂相比,温度和无机盐对复配物的CMC影响均不大,说明复配体系的抗温变及抗盐能力均有增强。

Surface tension and critical micelle concentration (CMC) of mixtures containing lauryl methyl ester ethoxylate (LMEE) and sodium dodecyl sulfate (SDS) were determined.Effect of temperature and inorganic salts were investigated,too.The results showed that the surface tension isotherms obtained for surfactant mixture lay between the isotherms for individual nonionic and ionic surfactants, but they were shifted toward the isotherm of the nonionic surfactant.The experimental results also showed that CMC of the mixture system were lower than those of single surfactants,the minimum value being 3.8×10^(-5) mol/L at 25 ℃ without added salt.The CMC slightly decreased as temperature increased.CMC and surface tension of the surfactant mixture at certain mixing ratio did not depend on the temperature.Addition of inorganic salts led to reduction of CMC too,but the influence was insignificant.